In a component mounting apparatus for mounting components on a circuit-formed member such as a resin boards or the like, it is important to recognize a component and to determine a correction quantity with respect to a placing position on the circuit-formed member for placement of the component onto the circuit-formed member on basis of a result of this recognition before the placement of the component on the circuit-formed member, in order to improve an accuracy of placement and a rate of placement in placement of components.
FIG. 10 shows a conventional component mounting apparatus 100 for mounting components 1 onto a resin board 2 as an example of a circuit-formed member. The resin board 2 is a printed board on which a circuit pattern has been formed for mounting of components 1 that are electronic components, and the resin board 2 is held on an XY-table 8. Parts cassettes 4 provided in a component feeding device 3 contain the components 1 by taping, and the components 1 are sucked one by one at a component sucking position 9 from the parts cassettes 4 by suction nozzles 5 provided on a nozzle unit 6 that makes a unidirectional intermittent rotational motion clockwise in FIG. 10 along an annular path 12.
After a suction operation at the component sucking position 9, the nozzle unit 6 moves along the path 12 to a component recognizing position 10, and suction status of the components 1 sucked on the suction nozzles 5 of the nozzle unit 6 are recognized in a predetermined space by a component recognizing device 7. A control device 20, into which information obtained from the component recognizing device 7 on recognition of the components 1 has been inputted, calculates correction quantities for the placement on basis of this component recognition information and stores the correction quantities in a correction quantity storage section 20c. After this recognition of the components 1, the nozzle unit 6 moves along the path 12 to a component placing position 11.
The control device 20 then calculates coordinates of a placing position on the resin board 2 on basis of coordinates on the resin board 2 registered in NC data read from an NC data storage section 20a and on basis of a corresponding correction quantity stored in the correction quantity storage section 20c, and calculates a turning angle of this suction nozzle 5 for angle correction on basis of the correction quantity. The control device 20 turns the suction nozzle 5 about a central axis thereof on basis of this calculated turning angle, and actuates the XY-table 8 to move the resin board 2 on basis of the calculated coordinates of the placing position on the resin board 2. When the nozzle unit 6 is positioned at the component placing position 11, the components 1 sucked by the suction nozzles 5 of the nozzle unit 6 are placed on the resin board 2.
FIG. 11 shows a deviation ΔL and an inclination Δθ relative to a normal suction status 1b of a component 1 sucked by a suction nozzle 5. The normal suction status 1b of the component 1 refers to status in which a center of gravity 1a of the component 1 coincides with a central axis 5b of the suction nozzle 5 as shown by broken lines in FIG. 11. In the component mounting apparatus 100, as described above, the components 1 are held with suction by the suction nozzles 5 and are placed onto the resin board 2. In a suction operation shown in FIG. 10 at the component sucking position 9, a deviation of a component 1 by the deviation ΔL may be caused as shown in FIG. 11 by a positional variation of the components 1 in cavities of a tape provided in the parts cassettes 4, a variation in status of attachment of the suction nozzles 5 in the component mounting apparatus 100, or the like.
Even if the center of gravity 1a of a component 1 is not aligned with the central axis 5b of the suction nozzle 5 when the component 1 is sucked by the suction nozzle 5, the component 1 is conveyed at a conveyance velocity that has been set originally, by a nozzle unit 6 that travels along the path 12 shown in FIG. 10. Accordingly, a moment acting on the component 1 increases with the deviation ΔL shown in FIG. 11 because an inertial force is exerted on the component 1 in accordance with an acceleration in the travel of the nozzle unit 6. As a result, while the nozzle unit 6 travels after the component recognizing device 7 recognizes the components 1, to calculate the correction quantities, until the components 1 are placed at the component placing position 11, moment forces tending to cause the components 1 to deviate from central axes 5b of the suction nozzles 5 act on the components 1, so that the components 1 on lower ends 5a of the suction nozzles 5 may further deviate from the status in the recognition of the components. In the conventional component mounting apparatus 100, therefore, there is a possibility that a position of a component 1 placed onto the resin board 2 may deviate from the placing position on the resin board 2 based on the NC data and the component recognition information on condition that the component 1 is placed on the resin board 2 only with a position correction based on the correction quantity.
Though the above conventional art has been described with reference to component mounting apparatus 100 of rotary type, a change in deviation caused after the recognition of components cannot be corrected even in a component mounting apparatus of XY-robot type in which nozzle units 6 having suction nozzles 5 can be moved freely in an XY-plane.
The present invention has been made for solving the problems described above, and an object of the present invention is to provide a component mounting apparatus and a component mounting method that improve an accuracy and a rate of placement of components onto a circuit-formed member.